Determining hydrogen positions in crystal engineered organic molecular complexes by joint neutron powder and single crystal X-ray diffractionElectronic supplementary information (ESI) available: Final Rietveld fits for all neutron powder diffraction data, tables of bond distances involving H atoms. See DOI: 10.1039/c3ce42070a

• Main Authors: Schmidtmann, Marc, Coster, Paul, Henry, Paul F, Ting, Valeska P, Weller, Mark T, Wilson, Chick C
• Format: Article
• Language: English
• ISSN: 1466-8033
• DOI: 10.1039/c3ce42070a

The potential of neutron powder diffraction (NPD) to provide vital information on the determination of accurate hydrogen positions in organic molecular crystals is demonstrated through the study of a series of hydrogen bonded molecular complexes with relevance in crystal engineering. By studying complexes designed to contain short, strong hydrogen bonds, the findings are shown to be of particular importance in the study of proton transfer, and the often critical distinction between neutral complexes and salts in these molecular materials. The use of combined NPD and single crystal X-ray diffraction is shown to be particularly potent in this area. Neutron powder diffraction is shown to add crucial information in studying proton transfer in molecular complexes with short hydrogen bonds, clearly distinguishing between neutral complexes and salts in these molecular systems.